1. Field of the Invention
The invention is to provide a ring body and supporting structure of vibratile gyroscope, and more particularly to a vibratile ring-shaped gyroscope that arranges a supporting structure at the axial side of the ring body.
2. Description of the Prior Art
A gyroscope is a device that measures a rotary angle or an angular velocity by the principle of inertia. Although the structure of a vibratile gyroscope is simple, its performance is outstanding. Since there are no rotary parts (e.g., bearing, etc.), so it is extremely suitable to be manufactured by micro-process technology. Currently, there are many kinds of micro gyroscopes on the market. Since the micro gyroscope has an advantage of low cost and a characteristic of medium, high performances with further tiny size, so it has extremely wide application range, such as: a satellite navigation and an orientation system. The micro gyroscope is a sensing element having a potential for development and commercialization.
Except the restriction of signal-to-noise ratio with respect to the signal pick-up circuit, another major factor influencing the performance (sensitivity) of the micro gyroscope is the design of its configuration. In various configurations of the vibratile gyroscope, since the ring-shaped vibratile micro gyroscope has a cyclic symmetry structure, relatively, it has a higher sensing sensitivity and an advantage of reducing an interference of surrounding vibration and an influence of temperature variation. However, under the pressure of the ring-shaped (circular) axially symmetric configuration, the performance of the ring-shaped vibratile micro gyroscope may be differentiated due to the different design of its partial structure.
Refer to FIG. 1, which shows a prior structure of a ring-shaped vibratile micro gyroscope (U.S. Pat. No. 5,450,751). The micro gyroscope 10 is arranged in a base 12 and includes: a side ring 14, a central column 15, and a plurality of semi-circular supporting structures 16 distributed divergently and equidistantly. A plurality of electrodes 13 are arranged around an outer periphery surrounding the side ring 14. The side ring 14 and supporting structures 16 are all manufactured by the techniques of micro mechanical electrical process with a high depth-to-width ratio. The structural height of the side ring 14 is the same as that of the supporting structure 16. By using different areas of the side ring 14 respectively, the micro gyroscope 10 provides the inductive areas needed by static-electrically driving and capacitance sensing electrodes. The inducing method of the micro gyroscope 10 is achieved by making different sections of the side ring 14 induced with the plural sensing/driving electrodes 13. The micro gyroscope 10 must depend upon the side ring 14 having a greater height to provide larger effective acting area. However, in the meantime of raising the height of the side ring 14, it may also accompany with the increase of structural strengths of the side ring 14 and the supporting structure 16 such that, under the operations of same static-electrically driving force and induced Coriolis force, the deformation of side ring 14 is reduced, so the structural radial deformation of micro gyroscope 10 (i.e., its sensing rate) is lowered down, and this is disadvantageous for raising its sensing sensitivity. Additionally, since the supporting structure 16 must occupy the inner side of the ring body 14, it is disadvantageous to install electrodes at an inner side and an outer side of the ring body 14 simultaneously.
There are prior arts cited, such as: “Angular Velocity Inductor” (ROC Patent No. 457370, U.S. Pat. No. 6,828,958 B1), “Angular Velocity Inducing Device” (ROC Patent No. 507077), etc., having the same structure of the above-mentioned conventional micro gyroscope 10, of which supporting structures are arranged at the inner side of the ring. Since they have substantially the same structures, repetitious description is not presented herein.
Refer to FIG. 2, which shows the structure of a ring-shaped vibratile micro gyroscope according to prior arts. The micro gyroscope 20, arranged in a base 22, is mainly comprised of ring body 24 and plural supporting structures 26. The main difference between this structure and the prior structure of FIG. 1 in the aspect of structural configuration is that the supporting structure 26 is divergently distributed around the ring body 24, so the radial area of entire micro gyroscope 20 is expanded; therefore, it occupies a larger space.